This invention relates to electric control apparatus and in particular to electric motor starters. Still more particularly this invention relates to a control button adaptor which is attachable to the starter to overlie a reset plunger and provide a finger-engagable button portion laterally offset from the reset plunger.
Electric motor starters comprise a power rated switching device and overload protection, commonly an electromagnetically operated contactor and an overload relay, usually mounted on a common mounting plate and electrically interconnected wherein individual poles of each device are connected in series. Through such apparatus, a motor is connected and disconnected from an electric supply by energization or deenergization of the contactor operating coil through a control element such as a manual switch, sensor or another relay. The overload relay of the starter monitors current flow through the apparatus to the motor to deenergize the contactor coil and disconnect the motor in the event of abnormal potentially harmful current flow to the motor.
Overload relays may selectively be made automatically or manually resettable. A depressible plunger or leveler, hereinafter referred to singularly as "plunger", is commonly provided in an overload relay for manually resetting the mechanism. Overload relay designs of thirty to forty years ago incorporated a finger-sized button directly on the end of the reset plunger, such button extending through, or being accessible through, a hole in an enclosure for the starter or in cabinetry of the apparatus in which the starter is used. In such designs the reset plunger was located at or near a midpoint between lateral edges of the relay. In more recent designs, the reset plunger is located at one side of the overload relay. As various models of starters are superseded by newer designs, the change in position of the reset plunger relative to the configuration of the starter presents a problem for original equipment manufacturers who have established mounting locations for the starter and any access openings in the apparatus cabinet wall. Also, in repair situations, when an updated starter is used to replace an older starter, the reset plunger will likely not align with the access opening in the cabinetry. Therefore, to enable customers to take advantage of updated technology in recent design starters and to permit the manufacturer of the starter to phase out old design starters by providing newer technology devices that can be retrofit into the same mounting situation as the older device, the control button adaptor described herein has been provided.